preferences of rhodamine coupled (aminoalkyl)-piperazine ... · preferences of rhodamine coupled...
TRANSCRIPT
S1
Preferences of rhodamine coupled (aminoalkyl)-piperazine probes
towards Hg(II) ion and their FRET mediated signaling
Biswonath Biswal and Bamaprasad Bag*
Colloids and Materials Chemistry Department, CSIR-Institute of Minerals and Materials
Technology, P.O.: R.R.L., Bhubaneswar-751 013, Odisha, India. Email: [email protected]
Supplementary information
Materials and Methods: S2
Absorption and emission spectral of 1 -4 in various solvents: S3-S4
Absorption peak position (λ, nm), corresponding molar S5
extinction coefficients (ε, dm3
mol-1
cm-1
) and emission
maxima of the probes 1-4 in different solvents (Table-ST1)
Metal ion induced optical signal modulation under
various conditions, determination of association constants,
Solid state fluorescence profile: S6-S12
Characterization (NMR and ESI-MS) Spectra: S13-S19
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S2
Materials and Methods
All the reagent grade chemicals were used without purification unless otherwise
specified. Rhodamine B, rhodamine-6G, 1,4-bis-(aminopropyl)-piperazine, anthracene-9-
carboxaldehyde, 4-chloro-7-nitrobenzofurazan, 1-(2-aminoethyl)-piperazine and metal
perchlorate salts were obtained from Sigma-Aldrich (USA) and used as received. Anhydrous
sodium sulfate, sodium borohydride, triethylamine, acids, buffers and the solvents were received
from S. D. Fine Chemicals (India). All the solvents were freshly distilled prior to use following
the literature procedures and the reactions were carried out under N2 atmosphere.
Chromatographic separations were done by column chromatography using 100–200 mesh silica
gel.
The compounds were characterized by elemental analyses, 1H-NMR,
13C-NMR and mass (ESI)
spectroscopy. 1H-NMR and
13C-NMR spectra were recorded on a JEOL JNM-AL400 FT V4.0
AL 400 (400 MHz and 100 MHz respectively) instrument in CDCl3 with Me4Si as the internal
standard. Electrospray mass spectral data were recorded on a MICROMASS QUATTRO II triple
quadruple mass spectrometer. The dissolved samples of the compounds in suitable solvents were
introduced into the ESI source through a syringe pump at the rate of 5µL/min, ESI capillary was
set at 3.5 kV with 40V cone voltage and the spectra were recorded at 6 s scans. Melting points
were determined with a melting point apparatus by PERFIT, India and were uncorrected.
Elemental analyses were done in an Elementar Vario EL III Carlo Erba 1108 elemental analyzer.
UV-visible spectra were recorded on a Perkin Elmer Lambda 650 UV/VIS spectrophotometer at
298 K in 10−4
-10−6
M concentration. Steady-state fluorescence spectra were obtained with a
Fluoromax 4P spectrofluorometer at 298 K. The solid-state emission spectra were also recorded
in Fluoromax 4P spectrofluorometer at 298K excited at requisite wavelength with 450WXenon
lamp, band pass 2 nm and slapped through 1 nm during recording the spectra with integration
time 0.2 s.
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S3
300 400 500 600 700 800
0
1
2
3
4
5
Ab
s
Hexane
n-Pr-OH
CHCl3
DCM
THF
Ethylacetate
EtOH
MeOH
MeCN
DMF
DMSO
1
(a)
Wavelength (nm)
300 400 500 6000
1
2
3
4
Ab
s
Wavelength(nm)
Hexane
CHCl3
DCM
THF
Ethyl Acetate
PrOH
EtOH
MeOH
Acetone
1,4-dioxane
MeCN
DMF
DMSO
2
(b)
300 400 500 600 700 8000.0
0.2
0.4
0.6
0.8
1.0
Abs
Wavelength(nm)
DCM
CHCl3
EtOH
MeOH
Ethyl Acetate
DMF
DMSO
THF
3
(c)
300 400 500 600 700 800
0
1
2
3
4
Ab
s
Wavelength (nm)
Hexane
PrOH
CHCl3
DCM
THF
Ethylacetate
EtOH
MeOH
MeCN
DMF
DMSO
4
(d)
Fig. S1: Absorption spectra of 1 - 4 in various solvents. Conc. of probes: 1 × 10−4
M (for 1, 2
and 4) and 1 × 10−5
M (for 3).
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S4
550 600 650 700 750 800
Hexane
THF
DCM
CHCl3
Acetone
Ethylacetate
MeOH
EtOH
i-PrOH
MeCN
DMF
DMSO
Flu
ore
sce
nce I
nte
nsity (
a.
u.)
Wavelength (nm)
1
(a)
400 450 500 550 600 650 700
Flu
ore
sce
nce
In
ten
sity (
a.
u.)
Wavelength(nm)
Hexane
CHCl3
DCM
THF
Ethyl acetate
PrOH
EtOH
MeOH
Acetone
1,4-dioxane
MeCN
DMF
DMSO2
(b)
450 500 550 600 650 700 750 800
DCM
CHCl3
EtOH
MeOH
Ethyl acetate
Acetone
THF
DMF
DMSO
Flu
ore
scence I
nte
nsity (
a.
u.)
Wavelength(nm)
3
(c)
550 600 650 700 750 800
Flu
ore
scence I
nte
nsity (
a.
u.)
Wavelength(nm)
Hexane
CHCl3
DCM
THF
Ethyl acetate
Acetone
PrOH
EtOH
MeOH
MeCN
DMF
DMSO
4
(d)
Fig. S2: Fluorescence spectra of (a) 1, (b) 2, (c) 3 and (d) 4 in different solvents. Concentration
of the probes: [1] = 1×10−7
M, [2] = 1×10−6
M, [3] = 1×10−6
M and [4] = 1×10−7
M; λex = 500 nm
for 1 and 4, 365nm for 2 and 420nm for 3 respectively; emission and excitation band pass =
5nm; T= 298 K; The error in fluorescence spectral data is within 10 %. The fluorescence quantum
yields (φF) were calculated by comparison of corrected spectrum with that of rhodamine G (φF =
0.95) in EtOH taking the area under the total emission, which was calculated to be < 0.001 in
each case.
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S5
Table ST1: Absorption peak position (λ, nm), corresponding molar extinction coefficients (ε,
dm3
mol-1
cm-1
) and emission maxima of the probes 1-4 in different solvents. Probe Solvent λabs, nm
(ε, dm3 mol
−1 cm
−1)
λema Probe λabs, nm
(ε, dm3 mol
−1 cm
−1)
λema
1 Hexane 271 (11231), 310 (3905) 539, 587 4 270 (n. d.), 310 (n. d.) 539,587
DCM 276 (12483), 317 (4685) 575 276 (20085), 315 (7779) 576
CHCl3 276 (14509), 317 (5719) 569 273 (25207), 317 (9890) 541,579
THF 273 (38227), 312 (13539) 588 273 (12655), 314 (4682) 587
Acetone 413 (741) 540,587 n. d. 540, 588
1,4-dioxane 273 (21548), 312 (7650) 540,586 273 (33272), 312 (11824) 539,589
Ethylacetate 273 (12507), 312 (4523) 587 271 (17155), 312 (6272) 588
MeCN 274 (27067), 315 (9898) 539,589 273 (48044), 317 (15685) 540
MeOH 273 (49370), 314 (15056) 564 273 (28721), 315 (10140) 564
EtOH 273 (19056), 315 (7780) 561 272 (37808), 314 (12584) 559
i-PrOH 273 (37887), 314 (13199) 560 273 (35028), 312 (12134) 563
DMF 273 (8769), 317 (3182) 540,588 274 (42887), 315 (15162) 542,587
DMSO 274 (35078), 320 (13404) 539,587 274 (41780), 317 (16101) 540,588
Probe Solvent λabs, nm (ε, dm3 mol
−1 cm
−1) λem
b
2 Hexane 270 (n. d.), 312 (n. d.), 345 (n. d.), 364 (n. d.), 383 (n. d.) 387, 409, 433
DCM 317 (35033), 348 (25359), 366 (36056), 386 (35230) 391, 141, 440
CHCl3 317 (28033), 368(30904), 388 (28662), 349 (20837) 392, 141, 440
THF 279 (33719), 314 (18053), 348 (13671), 366 (20536),
386 (18820)
390, 412, 437
Acetone 347 (8191), 365 (11988), 385 (10820) 388, 411, 434
1,4-dioxane 315 (8179), 348 (6258), 366 (9595), 385 (9224) 388, 412, 437
Ethylacetate 314 (28033), 347 (21073), 364 (31533), 385 (30275) 387, 409, 436
MeCN 272 (15011), 323 (5845), 364 (6429), 383 (6028) 387, 411, 434
MeOH 272 (23146), 317 (9353), 345 (6573), 364 (9454), 383(8623) 387, 409, 432
EtOH 271 (27974), 315 (10629), 347 (7744), 364 (11578),
385 (10811)
388, 410, 432
i-PrOH 315 (26382), 347 (19421), 365 (28859), 385 (26814) 388, 410, 433
DMF 320 (11617), 348 (8117), 365 (12404), 385 (11382) 389, 412, 436
DMSO 321 (7025), 350 (4724), 368 (7573), 388 (7025) 393, 415, 440
3 Hexane 274 (n.d.), 322 (n. d.), 463 (n. d.) 518c
DCM 274 (87292), 321 (46235), 467 (40022) 520 c
CHCl3 274 (83202), 320 (47887), 467 (39235) 528 c
THF 271 (63460), 321 (51112), 463 (44977) 525 c
Acetone 345 (7230), 478 (17658) 521 c
1,4-dioxane 273 (3769), 320 (1555), 470 (1768) 540 c
Ethylacetate 273 (78061), 318 (39685), 460 (36780) 543 c
MeCN 273 (18702), 320 (9280), 467 (9365) 540 c
MeOH 276 (89775), 321 (46629), 470 (56404) 539 c
EtOH 273(62536), 320(29634), 467(33837) 537 c
i-PrOH 273 (26718), 316 (11373), 346 (s, 4079), 475 (11077) 535 c
DMF 276 (96533), 321 (49162), 474 (45629) 533 c
DMSO 273 (78005), 323 (39747), 477 (38398) 533 c
λex = a 500nm,
b 365nm and
c 420nm.
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550 600 650 700 750 8000.0
0.2
0.4
0.6
0.8
1.0
Norm
aliz
ed F
luo
rescen
ce
In
tensity
Wavelength (nm)
DCM
CHCl3
λex = 500 nm
4
Fig. S3: Normalized fluorescence spectra of 4 alone in CHCl3 and DCM (~ 1×10−7
M) upon
excitation at 500nm, showing broad structure-less exciplex like emission at 710nm.
0.0 0.2 0.4 0.6 0.8 1.00.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Abs
Mole Fraction {[3] / ([3]+[Hg(II)])}
λλλλobs
= 557nm
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Abs
Mole fraction {[3] / [3]+[Pb(II)]}
λλλλobs
= 470nm
3
Fig. S4: Complexation stoichiometry determination as a function of change in absorption of 3 as
a function of mole fraction of added metal ion in MeCN-H2O (9:1 v/v). It exhibited 1:2 Ligand-
Metal stoichiometry of complexation when observed at 557nm (a) with Hg(II) ion, however, an
1:1 (L:M) stoichiometry was observed on monitoring at 470nm (b) with Pb(II) ion. This renders
insight to the step-wise complexation of both Hg(II) ion to 3 in its ‘amino-propyl-amino’
receptors.
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S7
300 400 500 600 700 8000.00
0.05
0.10
0.15
0.20
0.25
0.30
Abs
Wavelength (nm)
3
3 + Mn(II)
3 + Fe(II)
3 + Co(II)
3 + Ni(II)
3 + Cu(II)
3 + Zn(II)
3 + Hg(II)
3 + Ag(I)
3 + Pb(II)
3 + Cd(II)
MeCN-H2O (9:1 v/v)
Fig. S5: Absorption spectra of 3 alone and in presence of various metal ions in MeCN-H2O (9:1
v/v). [3]: 1 × 10−5
M, [M(I/II)]: 1 × 10−4
M.
550 600 650 700 750 800
8.0 eq.
Flu
ore
scen
ce inte
nsity (
a.
u.)
Wavelength(nm)
0.0 eq.
Fig. S6: Fluorescence spectra of 1 alone and in presence of various equivalents of added Hg(II)
metal ions in MeCN-H2O (9:1 v/v), [1]: 1 × 10−6
M, λex = 500nm, RT, ex and em b. p. = 5nm.
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S8
0 1 2 3 4
0.0
0.1
0.2
0.3
0.4
Ab
s (
λo
bs
557 )
[Hg(II)] (x 10-5 M)
Equation y = ((a*h*k1*x)+b*h*k1*k2*x^2))/(1+k1*x+k1*k2*x^2)
Adj. R-S 0.99196
Value Standard Error
y a 0.00104 0.00951
y b 0.41627 0.01059
y k1 1.33371E-5 3.26475E-7
y k2 2.09573E-6 2.6239E-7
(a)
0 2 4 6
(( ((I-I
0)) )) 5
80
[Hg(II)] (µM)
Eqn. y = ((a*h*k1*x)+b*h*k1*k2*x^2))/(1+k1*x+k1*k2*x^2)
Adj. R-sqr. 0.99287
Value Standard Error
h 5E-7
a 1.062E-4 0.00172
b 0.54999 3.754E-5
k1 2.14236E6 11493.412
k2 3.66285E10 1.78432E6
(b)
Fig. S7: Plot of change in (a) absorbance and (b) fluorescence intensity of 1 as a function of
added [Hg(II)] ions in MeCN-H2O (9:1 v/v). Experimental conditions: Emission; [1]= 5 × 10−7
M, λex = 500nm, RT, ex. and em. b. p. = 5nm; Absorption: [1]= 2 × 10−5
M. The plots determine
the binding constants k1 and k2 for step-wise complexation of both Hg(II) ion and exhibit their
positive cooperativity of complexation with 1.
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0 1 2 3 4 5 6
0.00
0.05
0.10
0.15
0.20
0.25
0.30
(A-A
0) 5
57
[Hg(II) (10µM)
Eqn. y = ((a*h*k1*x)+b*h*k1*k2*x^2))/(1+k1*x+k1*k2*x^2)
Adj. R-S
quare
0.99844
Value Standard Error
h 1E-5
a 0.00171 7.64E-5
b 2.68915E-5 0.00287
k1 16334.7149 104.86946
k2 1.73876E7 48397.0518
2
(a)
Fig. S8: Plot of change in absorbance of 2 as a function of added [Hg(II)] ion concentration in
MeCN-H2O (9:1 v/v), [2] = 1 × 10−5
M.
400 450 500 550 600 650
4.0 eq.
1.6 eq.
4.0 eq.
1.6 eq.
Flu
ore
sce
nce
Inte
nsity (
a.
u.)
Wavelength(nm)
0.0 eq.
1.5 eq.
Fig. S9: Fluorescence spectra of 2 alone and in presence of various equivalents of added Hg(II)
metal ions in MeCN-H2O (9:1 v/v), [2]: 1 × 10−6
M, λex = 365nm, RT, ex and em b. p. = 5nm.
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S10
0 3 6 9 4 8 12 16
0
2
4
6
8
10
(I-I
0) 5
80
[Hg(II)] (µM)
Eqn. y =(1/(2*h))*((h+x+a)-(sqrt((h+x+a)^2-(4*(h)*x))))
Adj R sqr. 0.98999
Value std. error
h 1E-6
a (=1/Ks) 6.02895E-9 2.18363E-11
(a)
(A-A
0)/
(Ali
m-A
) (x
100)
[Hg(II)] (x10µM)
Eqn. y = a + Ks * x
Adj R sqr 0.99278
Value Std. error
a Intercept -3.98252 0.34911
Ks Slope 5.50337E6 1512.01345
(b)
Fig. S10: Plot of change in (a) absorbance and (b) fluorescence intensity of 4 as a function of
added [Hg(II)] ion concentration in MeCN-H2O (9:1 v/v). Experimental conditions: Emission;
[4]= 1 × 10−6
M, λex = 500nm, RT, ex and em b. p. = 5nm; Absorption: [4]= 1 × 10−5
M.
0 1 2 3 4 5 6 7 8
(I-I
0) 5
80
[Hg(II)] (µM)
3
MeCN-H2O(9:1 v/v)
Eqn. y = ((a*h*k1*x)+b*h*k1*k2*x^2)) /(1+k1*x+k1*k2*x^2)
Adj. R-Squ 0.99219
Value Standard Err
h 5E-7
a 3.06459 0.04745
b 4.97658E-6 3.42906E-8
k1 969864.7160 56999.24479
k2 1.83549E10 3.03573E6
Fig. S11: Plot of change in fluorescence intensity (I580) of 3 as a function of added [Hg(II)] ion
concentration in MeCN-H2O (9:1 v/v). Experimental conditions: Emission; [3]= 5 × 10−7
M, λex
= 465nm, RT, ex and em b. p. = 5nm.
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400 450 500 550 600 650
Fl. I
nt.
(a
. u.)
Wavelength (nm)
2 [MeCN]
2 + H+ [MeCN]
2 [MeCN-H2O(9:1 v/v)]
2 + H+ [MeCN-H
2O(9:1 v/v)]
Fig. S12: Fluorescence spectra of 2 alone and in presence protons (H+) in both MeCN and
MeCN-H2O (9:1 v/v), [2]: 1 × 10−6
M, λex = 365nm, RT, ex and em b. p. = 5nm.
400 450 500 550 600 650 400 450 500 550 600 650
Fl. I
nt.
(a
. u
.)
Wavelength (nm)
2 [MeCN]
2 [MeCN-H2O (9:1 v/v)]
2 [MeCN-H2O (7:3 v/v)]
2 [MeCN-H2O (1:1 v/v)]
Fl. I
nt.
(a
. u
.)
Wavelength (nm)
2 [pH =4.0]
2 [pH =7.0]
2 [pH =10.0]
Fig. S13: Fluorescence spectra of 2 in (a) various propertions of aqueous – organic mixture
(MeCN-H2O) and (b) at different pH. [2]: 1 × 10−6
M, λex = 365nm, RT, ex and em b. p. = 5nm.
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S12
400 450 500 550 600 6500.0
0.2
0.4
0.6
0.8
1.0
Norm
aliz
ed f
luo.
Int.
Wavelength (nm)
2
2.(Hg(II))2 Complex
Fig. S14: Normalized solid state fluorescence spectra of 2 and its Hg(II)-complex (λex = 365nm).
550 600 650 700 750 800
Flu
ore
scence I
nte
nsity (
a.
u.)
Wavelength(nm)
Blank
Cl-
PO4
3-
NO3
-
I-
HCO3
-
SCN-
SO4
2-
AcO-
En
EDTA
Fig. 15: Fluorescence spectral of saturated solution containing 1 (1 equiv.) and HgII (5 equiv.)
upon addition of various anions (10 equiv.) and chelating agents such as ethylenediamine and
EDTA. [1] = 5 ×10−7
M, MeCN-H2O (9:1 v/v), [2]: 1 × 10−6
M, λex = 500nm, RT, ex / em b. p. =
5 nm.
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S13
Fig. S16: ESI-MS of 1.
Fig. S17: 1H-NMR spectra of 1 in CDCl3
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Fig. S18 :
13C-NMR spectra of 1 in CDCl3.
Fig. S19:
1H-NMR spectra of 2 in CDCl3.
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Fig. S20: 13
C-NMR spectra of 2 in CDCl3
Fig. S21: ESI-MS of 2.
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Fig. S22: 1H-NMR spectra of 3 in CDCl3
Fig. S23: 13
C-NMR spectra of 3 in CDCl3
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S17
Fig. S24: ESI-MS of 3.
Fig. S25: 1H-NMR spectra of 4 in CDCl3
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Fig. S26: 13
C-NMR spectra of 4 in CDCl3
Fig. S27: ESI-MS of 4.
Electronic Supplementary Material (ESI) for Organic & Biomolecular ChemistryThis journal is © The Royal Society of Chemistry 2013